1. Field of the Invention
The present invention relates generally to a method for constructing a service providing system, such as a system for monitoring an external apparatus. More specifically, the invention relates to a method for constructing a serving providing system using a framework for service providing system, which is described by an object-oriented language or the like; a service providing system constructed by the method; and a computer readable recording media in which a program for service providing system or a framework for service providing system has been recorded.
2. Description of the Related Art
As a service providing system for providing service for an object system, there is known a monitoring system for exchanging monitoring instructions and monitored results with an external apparatus (an object system) serving as a service provided object to provide various services, such as the setting of initial data, build-up and tabulation of data, for the external apparatus. Such a monitoring system is generally constructed as a software capable of being executed on a computer system. In such a monitoring system, specification change and extension are carried out in accordance with the kind of external apparatuses serving as an object to be monitored, the kind of screens for interface provided between the monitoring system and a user, the kind of data used in the external apparatus, and the kind of services provided for the external apparatus.
However, any reference models for uniformly expressing the configuration of monitoring systems and service are not conventionally established, so that there are problems in that if specification change or extension is carried out, the architecture of the software is likely to be unstable, and the reusability and change facility of the software can not easily be ensured.
For example, in conventional monitoring systems, internal data handled in the monitoring system are not distinguished from communication data reflecting a communication protocol between the monitoring system and the external apparatus, and communication data exchanged between the monitoring system and the external apparatus are stored in the monitoring system as they are. The stored data are suitably referred and updated to carry out various services. Therefore, as shown in FIG. 31, if the communication protocol between the monitoring system and the external apparatus is changed, the change of the communication protocol influences the whole monitoring system although the service on the side of the monitoring system is not changed.
Specifically, if the order of items of the communication data and the data structure thereof are changed in accordance with the change of the communication protocol, the order of items of data is changed in the monitoring system, and the data structure thereof is changed therein, for example, from bytes to bits. In addition, such change of the data structure also influences other system configurations in the monitoring system for referring to and updating the data, so that it is required to change methods for referring to and updating the data.
In addition, a sequence itself is sometimes changed in accordance with the change of the communication protocol. For example, if an external apparatus serving as an apparatus to be monitored is changed from an old style apparatus to an advanced apparatus or to an apparatus produced by another company, it is often required to change the sequence in accordance with the setting on the side of the apparatus and so forth. In this case, examples are shown in FIGS. 32A and 32B. As shown in FIGS. 32A and 32B, an external apparatus A uses a sequence wherein if monitoring instructions are issued from the side of a monitoring system, processing is carried out on the side of the external apparatus to simply return monitored results. In addition, an external apparatus B uses a sequence wherein if monitoring instructions are issued from the side of a monitoring system, a receipt (a notice meaning that monitoring is not executed although monitoring instructions are received) is once returned from the external apparatus, and thereafter, processing is actually carried out on the side of the external apparatus to return monitored results. Therefore, if the apparatus is changed between such external apparatuses A and B, it is required to change the sequence.